Safety two-hand control



Oct. 19, 1943. E. DAVIS SAFETY TWO-HAND CONTROL Filed May 5, 1942 4 Sheets-Sheet l INVENTOR I ERNEST DAVIS BY @wM/M FIG-3 ATTOR NEYS Oct. 19, 1943. E. DAVIS SAFETY TWO-HAND CONTROL Filed May 5, 1942 4 SheetsSheet 2 INVENTOR E R N E ST DAVIS ATTORNEYS Oct. 19, 1943. E. DAVIS 2,332,132

SAFETY TWO-HAND CONTROL Filed May 5, 1942 4 Sheets-Sheet 4 INVENTOR E R NEST DAVIS BY flawed! ATTORNEYS Patented Oct. 19, 1943 SAFETY TWO-HAND CONTROL Ernest Davis, Syracuse, N, Ya, assignor to The.

Prosperity Company, 1110., Syracuse, N. Y., a

corporation of New York Application Ma 5, 1942, Serial No. 441,321

7 Claims. (01. 192-431) This invention relates to safety two hand con-- trols for machines having a dangerous operating movement, as various types of power presses, including garment and laundry presses, and other machines having an opening and closing movement. It has for its object a particularly simple construction of two hand control requiring that the two manuals be operated substantially in uni-,

son and including a pair of pistons actuated or controlled in their actuation by the manuals with the joint action of th pistons in unison being required to effect the operation of the control element controlling the operation of the machine.

It further has for its object a twohand control mechanism involving two pistons in which the operation of the two pistons in unison effects the operation of a single motion transmitting member, which'in turn operates the control element of the machine. I v

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed. 1

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts inall the views.

Figure 1 is a plan view, partly broken away, of this two hand control, the contiguous portion of the garment or laundry pressingmachine being shown.

Figure 2 is an enlarged side elevation of the control, the contiguous portion of th frame and table of the machine being also shown.

Figure 3 is a perspective View, on a reduced, scale, of one type of pressing machine embodying this invention. I

Figure 4 is an enlargedsectional view on the Figure 8 is an enlargedfragmentary sectional view of one of the pistons. I

Figure 9 is a face view of both pistons.

Figure 10 is a fragmentary longitudinal sectional viewshowing the piston as discoidal and the piston chambers as cylindrical and located nearly tangent, with the separating wall perforated throughout its length. l

Figure 11 is a. sectional view takenon line HH,Figure 10.

Figure 12 isa fra'gmentary'sectional view of a modified form of the control in whichthe piston chambers are fixed, the movements of the piston transferred by displacing the fluid to a pres-f' sure operated-device or bellows. v

This two hand control includes, generally, a

, member formed with a'pair of parallel piston chambers, which communicate with each other along adjacent sides, pistons'working in the chambers, manually controlled means for actuat-' .ing the pistons individually, whereby "upon the individual operation of either piston only, the

fluid in the chamber for that" piston flows or displaces into the other chamber and around the operated piston from'the pressure side to'the rear side thereof, and themotion of both pistons when operated in unisonis transferred by the hind in both of said chambers on the Pressure sides thereof, to a motiontransmitting device for operating a power control element, as a valve;

In "the form shown in Figures 1 to 10, the piston chamber member is in the form of a motion transe:

mitting lever and the operation of the pistons in unison efiects the shifting or pivotal action of the shiftable member or lever., The pivotal action of the shiftable member operates the control element of a power operated machine to which the two hand controlis applied. The shiftable member is also formed to provide a reservoir for a fluid, as a hydraulic fluid, for supplying fluid to the pist-onflchambers on the pressure sides of the piston. The piston chambers are however, not provided with any return outlet,but the pistons are formed with check valve controlled passages operable to permit the transfer of any liquid on-the rear or non-pressuresides'. of the pistons to the pressure sides thereof dur-,

ing return movement of the, pistons to starting position. The shifting movement of the lever is thus coaxial with thepivotal axis of the lever formation. The shafts 3, 24 are journalled in brackets 5 having a common'base 6 attached to the frame I of the machine to which the two hand control is applied. This pivoted arm of the angle lever I is provided with a suitable re movable cap 8 for giving access to the interior of the lever. The other arm 9 of the angular formation is provided with a receptacle or cylinder III which is usually a separate part from the major portion of this arm 9.

II and I2 designate pistons working in the receptacle or cylinder. As shown in Figures 5, 6 and 9, these pistons are each semi-discoidal in form and work in opposite halves I3 and I4 of the cylinder, and hence the halves of the cylinder constitute chambers for the pistons II and I2 respectively, which chambers communicate with each other throughout their adjacent sides, or as here illustrated, along a diametrical plane of the cylinder I0, although these chambers may be separate bores I3 and I4"- (Figures 10 and 11) opening into each other, where they run tangent to each other and the pistons Il I2 may be discoidal. p

The portion of the hollow lever formation be yond or above the pistons II and I2 constitutes a reservoir or sump at I5 for a hydraulic fluid. I6 and I1 designate the piston rods, each being semi-cylindrical in cross-section, the rods extending up into the angular portion of the lever I. The cylinder I is also provided with transfer passages I8 located to permit the fluid to flow from the reservoir I to in front of the pistons when the pistons are in their starting or neutral position, as shown in Figures 4 and 5. These passages are cut off or covered, upon initial movement of the pistons bythe manuals. The pistons are here shown as formed with passages I9 therethrough and with check valves arranged to close said passages, when the pistons are on their compression strokes. The valves 20 are shown as merely arcuate strips suitably secured to the faces of the pistons, as by screws or guide rods.2I, the valves being slidable on the rods into and out of position to close the passages I9 during the compression movement of the piston and open them upon retrograde movement of the pistons respectively.

.The shafts 3, 4 are rock shafts,'whichare manually operable, and as seen in Figure 1, each shaft is provided with a rock arm 22 or 23 thereon provided with a handle 24 or 25. The two hand control mechanism is located below the table 26 of the pressing machine and the handles 24, are shown as platesnormally lying flush with the table at the edge thereof. The rock shafts 3,1 are individual to the piston rods I6, 1'! respectively, and are connected thereto by suitable motion transmitting means, here illustrated as rock arms 21, 28 on said shafts 3, 4. respectively, these extending lengthwise of the pivoted arm of the lever I and being "connected to the piston rods I5, II respectively in the angular portion of the lever formation. Upon the operation of only one manual, for instance as the right hand manual (Figure 6), the right hand piston II only is actuated, and hence during its actuating movement, the fluid displaces around the piston II to the rear or non-pressure side thereof, and hence during its actuating move ment, such operation of the right hand manual and shaft 3 is ineffective. However, upon the actuation of both manuals and rockshafts 3, 4 in unison, both pistons are actuated and their actuating force transferred to the lever I, causing it to rock about the axis of the shafts 3, 4 against the action of a returning spring 29, this action opening the control element of the power mechanism of the machine to which the two hand control is applied. The pistons are returned to their starting position, upon the release of the manuals, by returning springs 30, acting on rock arms 3| (see Figure 2) on the shafts 3, 4.

In the illustrated embodiment of this invention, the motion transmitting lever I is shown as actuating a control valve for a motive fluid. 32 designates a control valve of the combined intake and exhaust type having a normally open exhaust valve head 33 and a normally closed spring pressed intake valve head 34, these being connected together, so that they act as a unit. The intake end of the casing 32 is connected to a source of supply of power fluid, as compressed air, by a pipe 35. The exhaust is provided with an exhaust port 35. The intermediate part of the casing is connected by a pipe 31 to a pneumatic motor, as a cylinder and piston motor utilized to actuate the movable element of the press .to which the two hand control is applied. This valve 32 is carried in any suitable manner by the frame "I of the machine, as by a bracket 39. The valve member or unit provided with the intake and exhaust valve heads 33, 34 operated by'the pivotal movement of the lever I, as by an arm 40 on the lever I carrying an adjustable screw 4| which thrusts against the head 42 on the stem 43 of the exhaust valve head 33, which stem extends outside of the casing of the valve 32. Thus, when both manual levers 22, 23 are operated in unison, and hence both pistons II, I2 are operated, the lever I will be shifted from the position shown in Figure 1 to that shown in Figure '7, and hence the arm 40 will open the intake valve head 34, and close the exhaust valve head 33, from the position shown in Figure 6 to that shown in Figure 7, permitting the air to flow through the casing of the valve 32 and pipe 31 to the motor of the pressing machine to actuate the mechanism of said machine. This control valve may be held in its operated position after the manuals have been released in any well known manner. Also, the valve 32 may be released after being so held in any well known manner.

This two hand control is particularly adapted for that type of machine which has a dangerous opening and closing movement to the operator, as a garment and laundry machine (Figure 3), in which a press head or platen is carried by a lever 5| to move toward and from a platen or buck 52. The lever 5| is actuated by a motor, as a cylinder and piston motor, and the flow of air to the motor controlled by the valve 32.

In the general operation, with the press head 50 in open position, the operator must depress both manuals 24, 25 simultaneously or in unison, and thus effect the simultaneou rocking of both shafts 3, 4, in order to effect the operation of both pistons I I, I2 in unison, and thus cause the lever I to be rocked to open the intake head of the valve 32 and close the exhaust valve head. If only one manual is operated, only one piston II or I2 is.actuated, as seen in Figure 6, and the pressure of the hydraulic fluid ineffective to rock the lever I to operate the valve 32.

In Figure 12, the double piston chamber 54 is stationary or fixed to the frame and communicates through a pipe '55 with a pressure operated device as a bellows or Sylphon 56 having a head 51 which operates the stem 43 of the control valve 32 (Figures 6 and 7). r

In machines of this type, means is provided for requiring the operator to hold both manuals depressed or operated, until the press head 50 I closes, or to release andrpermit the head 50 to i open in the event one or both manualsis re- 1. A twohand control including a pair of pistons, manually controlled means. for operating the piston individually and means for transferring through pressure fluid the movement of the pistons, when operated in unison, comprising a member formed with piston chamber communicating with each other along their sides, whereby a pressure fluid displaces from the pressure side of either piston to the opposite side when only one piston is operated, in combination with an element for controlling the operation of the machine to which the two handcontrol is applied and operable by the pressure fluid, only when both pistons are operated in unison.

2. A two hand control including a pair ofpistons, manually controlled means for operating the pistons individually and means for transferring through pressure fluid the movement of the pistons, when operated in unison, comprising a memberformed with piston chambers communicating with each other along their sides,

whereby a pressure fluiddisplaces from the pressure side of either piston to the opposite side when only one piston is operated, thepistons having check valve controlled passages for permitting the flow of fluid'on the rear sides of the pistons to the pressure sides during the retrograde movement of the pistons; in combination with an element for controlling the operation of the machine to which the two hand control is applied and operable by the pressure fluid, only when both pistons are operated in unison.

3. A two hand control comprising a pair of pistons, a shiftable member formed with parallel chambers in which the pistons operate, the chambers communicating with each other along their sides, manually controlled means for operating the pistons individually, whereby upon the individual operation of either piston only, the fluid in the chamber of that piston flows into the other chamber and around the operated piston from the pressure to the rear side thereof and upon operation of both pistons in unison compresses the fluid in both said chambers and transmits the movement of the pistons to the shiftable member; in combination with an element for controlling the operation of the machine to which the two hand control is applied, operable by the shifting movement of said member.

4. A. two hand control comprising a shiftable member in the form of a pivotally mounted, hollow lever formed with parallel piston chambers communicating along their sides with each other, individually operable pistons movable in the chambers, means for operating the pistons including rock shafts arranged coaxially with the pivotal axis of the shiftable member, motion transmitting means'between the rock shaftsand the piston respectively,the pistons having check valve controlled: passages forpermitting the flow of any fluid on the rearsides of the pistons to the pressures sides thereofjduring retrograde movement of the pistons; in combination with an element for controlling the operation of the machine to which the twohand control i applied; said element being operable bythe shift-. ing movement of said shiftable member.

5. A two hand control including a shiftable member in the form of an angle lever, one arm of the lever being pivotally mounted, the other arm of the'lever being formed with parallel piston chambers communicating along their adjacent sides with eachother, individually operable v pistons movable. in the chambers and having rods extending toward the angle of the shiftable member, individually operable rockshaft mounted coaxially with the pivotal-axis of the leverand .i extending into the samefrock arms mounted within the lever on the, shafts respectively and" extending lengthwise of thepivoted arm of the lever and connected to the piston rods in the angle of thelever; in combination with an element for controlling the operation of the machine to which'the two hand control is applied,

said element being operable by the shifting move- 'ment of said member.

6. A two hand control including a shiftable member formed with a chamber for a hydraulic fluid, a pair of pistons individually movable in I said chamber, manuallyv controlled means for I operating the pistons individually, said member being also formed with a reservoir for supplying fluid to the chamber andcommunicating there with, when the pistons are in starting position and permitting the outflow of fluid when the I fluid is displaced by the operation of one piston only, the operation of the pistons inunison closring the chamber to the inlet and outlet of fluid,

whereby the motion of the pistons is transferred by the fluid-to said shiftable member to shift the same; in combination .With an element ,for

the two hand control is applied, operable by the shifting movement of said member, and means- Y tending to return the pistons individually totheir starting positions.

voir closed by the operating movement of the pistons, said passages permitting displacement is operated and preventing the displacement when both are operated in unison, whereby the movement of both pistons is transmitted by the fluid in the receptacle to said shiftable member; in combination with an elementfor controlling the operation of the machine to which the two hand control is applied operableby the shifting movement of said member.

. ERNEST DAVIS.

controlling the operation of the machine to which,

. '7. In a two hand control comprising a shift- Q able member formed with a closed receptacle for out of the receptacle only when one piston only 

